The anti-tumor effect of cyanidin-3-glucoside on lung cancer in vitro and in vivo

Abstract

Objective To investigate the effect and the mechanism of cyanidin-3-glucoside in the growth inhibition of lung cancer.Methods After human lung cancer cell line H1299 was treated with cyanidin-3-glucoside,the cellular proliferation was detected by methyl thiazolyl tetrazolium(MTT)assay.H1299 cells morphological changes were observed under the fluorescence microscopy after DAPI staining.Western blot was used to detect the expression of XIAP and Smac in lung cancer cells.H1299 cells were injected subcutaneously into nude mice to establish xenograft model.After 2 weeks of implantation,mice were randomized into 2 groups(n=8):Control group,feed with 0.2 ml double distilled water;Test group,feed with cyanidin-3-glucoside at dose of 5 mg/kg.All treatment lasted for three weeks,thrice per week.Eight weeks after implantation,tumor weight and inhibition rate were evaluated respectively after the mice were sacrificed.Immunohistochemistry was used to detect the positive expression of Ki-67,XIAP and Smac in the tumors.Results The proliferation of lung cancer cells was inhibited significantly by cyanidin-3-glucoside with IC50 being 14.5 μg/ml.Cyanidin-3-glucoside induced a higher percentage of apoptosis in H1299 cells when compared with the control.The expression of XIAP and Smac were down-regulated and up-regulated,respectively in H1299 cells after treatment of cyanidin-3-glucoside.The final tumor weight showed significant decrease in the test group compared with control.Furthermore,the positive expression of Ki-67 and XIAP were decreased in tumors after treatment of cyanidin-3-glucoside,but the level of Smac was increased in test group compared with control.Conclusions Cyanidin-3-glucoside exerts anti-tumor activity in lung cancer both in vitro and in vivo,which may be related to down-regulation of XIAP and up-regulation of Smac protein.